Kennewick, Washington Weather
Thunder retreats as the monsoon dies. Day 93 of summer. Read this microseason across nine climate regions →
Kennewick weather forecast — hour by hour, 7-day outlook, NOAA radar
Conditions updated 1:00 AM PDT · Open-Meteo
- TodaySep 21Clear——88°58°—
- TuesdaySep 22Overcast——82°62°-6°
- WednesdaySep 23Overcast——78°56°-4°
- ThursdaySep 24Overcast——82°58°+4°
- FridaySep 25Heavy Drizzle17%0.07″71°54°-11°
- SaturdaySep 26Overcast——69°51°-2°
- SundaySep 27Overcast——72°52°+3°
Air quality now AQI 38 · Good
AQI 38 (Good), driven by PM2.5. AQI up 5 over the last 6 hours (gradual rise). PM2.5 at 5.8 µg/m³, PM10 at 6.5 µg/m³ — typical background levels with no transport signature.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
PM × Wind × Precip
PM2.5 at 5.8 µg/m³, PM10 at 6.5 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.89
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- background
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
September dries up ditches or breaks down bridges.
- Moonrise
- 4:52 PM
- Moonset
- 1:00 AM
- In sign
- ♑︎ Capricorn
Thunder retreats as the monsoon dies
Read this microseason across nine climate regions →
All 72 microseasons on the year wheel →
Kennewick at a glance
- Today vs. normal: Today averages 73°F (high 88°F, low 58°F), 9°F above the 64°F normal for Sep 21
- Last frost: March 28 (1991–2020 median, NOAA station 6 km away)
- Microseason: Sep 21–25
- Planting calendar: September — plant garlic (overwinter); harvest tomatoes, peppers, beans, summer squash, winter squash
15-Day Forecast — Kennewick
- Mon88°58°0%
- Tue82°62°0%
- Wed78°56°0%
- Thu82°58°5%
- Fri71°54°17%
- Sat69°51°4%
- Sun72°52°5%
- Mon78°53°1%
- Tue80°57°1%
- Wed80°60°4%
- Thu86°62°9%
- Fri80°60°10%
- Sat69°53°7%
- Sun70°48°6%
- Mon71°51°6%
Forecast data from Open-Meteo (CC BY 4.0).
Live wind & temperature near Kennewick
Interactive wind and temperature map centered on Kennewick — it loads in your browser. Open the full weather map.
Right now in the garden
Fall planting + final harvests
As of September 21, the season's first frost (typically October 30) is approaching. Pick what frost-tender plants still carry before the next cold front. This city's planting calendar for September: plant garlic (overwinter); harvest tomatoes, peppers, beans, summer squash, and winter squash.
Sun & seasons in Kennewick
Kennewick sits in Benton County, where the year’s longest day runs 15h 47m of daylight and its shortest just 8h 37m — a swing of +7h 10m between the June and December solstices. Clocks spring forward on Sunday, March 8, 2026 and fall back on Sunday, November 1, 2026.
Seattle, the state’s largest city, lies about 178 miles to the NW. The nearest town Kennewick tracks is Marine View, roughly 54 miles to the N.
Air quality in Kennewick
Air quality in Kennewick’s county has held roughly steady since 2020; its cleanest year on record was 2024 (median AQI 34). See the full air-quality history for Kennewick.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| March | lettuce, peas, spinach, radishes | radishes |
| April | lettuce, peas, spinach, radishes | lettuce, spinach, radishes |
| May | tomatoes, peppers, beans, squash | lettuce, peas, spinach, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, spinach, garlic |
| July | tomatoes, peppers, beans, squash | tomatoes, peppers, beans, summer squash, garlic |
| August | beans, squash, fall brassicas, carrots | tomatoes, peppers, beans, summer squash, winter squash |
| September | garlic (overwinter) | tomatoes, peppers, beans, summer squash, winter squash |
| October | garlic (overwinter) | tomatoes, peppers, beans, summer squash, winter squash, fall brassicas, carrots |
| November | — | fall brassicas, carrots |
A year in weather
Kennewick peaks at about 77°F in July and bottoms near 36°F in January; January brings the heaviest rain (1.1 inches) and August the least (0.2 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 36° | 1.1″ | 4 |
| February | 40° | 0.8″ | 3 |
| March | 47° | 0.7″ | 2 |
| April | 54° | 0.6″ | 2 |
| May | 63° | 0.8″ | 2 |
| June | 69° | 0.6″ | 2 |
| July | 77° | 0.2″ | 1 |
| August | 76° | 0.2″ | 1 |
| September | 67° | 0.3″ | 1 |
| October | 55° | 0.7″ | 2 |
| November | 43° | 0.9″ | 3 |
| December | 36° | 1.1″ | 4 |
Regional context
Similar climates West Pasco, WA, Pasco, WA, Finley, WA
Kennewick's climate, from NOAA NCEI 1991-2020 station normals, pairs 36°F Januarys with 77°F Julys — a 41°F swing. About 7.9 inches of precipitation falls over roughly 27 days a year.
Precipitation in Kennewick peaks in the cool season: January averages 1.1 inches across 4.0 storm-fed days, while August bottoms out at 0.2 inches over just 0.6 rainy days. That cool-season-wet pattern aligns Kennewick with places like West Pasco, WA, Pasco, WA and Finley, WA.
By March 28 the frosts ease in Kennewick, opening the season for peas, lettuce, spinach, and radishes. Hold Kennewick's tender crops — tomatoes, peppers, basil — until 10-14 days past Kennewick's last frost. It shuts near October 30, when freezes return to Kennewick and tender plants need cover. Sheltered Kennewick yards can escape a light frost.
Similar climates: West Pasco, WA, Pasco, WA, Finley, WA, Richland, WA, Burbank, WA.
Frequently asked
- When does it freeze in Kennewick?
- Kennewick's last spring frost lands near March 28, and in Kennewick the first fall frost follows around October 30.
- What is the rainy season in Kennewick?
- Kennewick sees its heaviest rain in January (around 1.1 inches), part of roughly 8 inches a year.
- What is the warmest month in Kennewick?
- On average July tops the year in Kennewick at about 77°F.
- What is the coldest month in Kennewick?
- The coldest stretch in Kennewick falls in January, around 36°F on average.
- When can I start a vegetable garden in Kennewick?
- Around March 28, start frost-hardy crops in Kennewick; tomatoes and basil belong a fortnight later.
- How many rainy days does Kennewick get?
- Kennewick records around 27 days of measurable precipitation annually.
- What hardiness zone is Kennewick?
- With January around 36°F, Kennewick's zone reflects that minimum — the USDA ZIP map confirms Kennewick's band.
- What is the 10-day forecast for Kennewick?
- Kennewick's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
- Will it rain this week in Kennewick?
- See this week's day-by-day rain chances for Kennewick in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Kennewick?
- Current conditions for Kennewick and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Kennewick forecast updated?
- The Kennewick forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Kennewick?
- Today's sunrise and sunset times for Kennewick are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
- How accurate is the weather forecast for Kennewick?
- The next few days in Kennewick's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Kennewick sits at 46.2°N; its climate zone is warm-summer Mediterranean (Köppen approximation).
ZIP codes in Kennewick
- 99336
- 99337
- 99338